Leaf decay does not occur. (Saplings still appear when manually breaking leaves, however). Tested on Acacia trees, will test on other trees and report back.
Edit: It appears that leaf decay works on trees added before 0.9.0 (Oak, birch, spurce, and jungle), but not on the 2 new tree types (Acacia and dark oak)
We're closing all issues only related to 0.6, 0.7 or snapshots of any version.
If you think that this issues applies to MCPE 0.9.5 or later, please comment here!